The present invention relates generally to a method of formulating lactating bovine rations. More particularly, the present invention relates to a method for obtaining desired changes in milk composition by formulating rations based on results obtained from abomasal infusion trials. This method allows the determination of the effects of ration ingredients that are not rumen protected. It allows for results of trials much more quickly than conventional feeding trials and it provides a practical formulation technology which was not possible before.
The composition of milk is increasingly becoming a concern to the diary industry because health conscious consumers desire a milk composition that has a decreased fat and saturated fat concentration and an increased protein concentration. If the diary industry is able to change the fat and protein composition of raw milk produced by cows, the dairy industry would be able to provide consumers with more of the products health conscious consumers prefer. Additionally, decreasing the fat concentration and increasing the protein concentration in raw milk would allow the diary industry to reduce the cost of processing raw milk into certain marketable products. It is also desirable to alter the fatty acid composition of the raw milk so that the fat in raw milk produced by cows is more healthful and requires less alteration during processing.
It is known that the composition of milk can be changed through the judicious feeding of different feed additives or feeds to cows. For example, a ration that promotes a low acetate to propionate ratio in volatile fatty acids produced in the rumen of the cow causes a significant decrease in milk fat percentage and minor increase in milk protein percentage. A problem with feeding cows a ration that promotes these beneficial characteristics is that the ration frequently cause health problems in the cows that consume it. The health problems include laminitis, displaced abomasum, and ruminal parakeratosis.
In addition to possible health problems, the ability to change milk composition by changing a cow's diet is limited because of alteration that the rations undergo in the rumen. For example, unsaturated fatty acids are readily hydrogenated in the rumen. Proteins are digested. Other compounds are altered, fermented, or cleaved. To avoid these undesired changes, the components in the ration must be processed so that the components are not modified in the rumen. The processed components that are resistant to modification in the rumen are referred to as rumen inert components. Once the rumen inert components pass through the rumen the rumen inert components are digested in the cow's abomasum and are absorbed in the small intestine.
The current practice is to modify ration components to make them rumen inert before it is known whether the ration components have a beneficial effect on the composition of milk. The ration components are then fed to cows and then the effect on milk composition is studied. Thus, researchers must go through the time and expense that is necessary to make ration components rumen inert before it is known whether the ration components will have a beneficial effect on the composition of the milk produced by the cow.